Teamsters union General President Sean M. O’ Brien told UPS that the union wants a tentative contract agreement within the next week that its leadership can support or that it will demand that the company present its last, best and final contract offer.

The escalating rhetoric, included in a Tuesday statement, comes as UPS (NYSE: UPS) purportedly returned to the bargaining table Tuesday morning in Washington without an updated counteroffer to present to the union. According to union sources, O’Brien harshly reiterated that the Teamsters will not work beyond July 31 without a new contract.

“When we say the current contract expires July 31, that means we want a new contract in place starting August 1. Not in six months. Not next spring. We demand a historic new contract August 1, with more money in our members’ pockets immediately,” O’Brien said in the statement. “UPS has wasted enough time and hoarded these record profits. Our members want what they have earned.”

Any tentative agreement would need to be endorsed by the Teamsters’ national committee before being properly disseminated and voted on by the membership by the end of the current agreement.

UPS was not immediately available to comment.

Before caucusing to review economic proposals, the Teamsters told UPS the union committed to working seven days a week and through the upcoming holiday weekend to get a deal done. 

“This is why there’s new leadership at the Teamsters. UPS isn’t working with the union’s prior administration, dragging out the bargaining process and submitting to extensions until finally agreeing to a watered-down deal months after the expiration of the contract,” said General Secretary-Treasurer Fred Zuckerman. “This is what hard bargaining looks like. This is labor’s leverage, and the Teamsters are not afraid to use it.”

Both sides have already concluded talks on noneconomic issues, tentatively agreeing to language covering 55 agreements. The union presented its initial offer to UPS last Wednesday to cover economic issues such as wages, benefits and changes in worker classifications. The union subsequently rejected UPS’ counteroffer as appalling, saying it calls for meager wage increases and takes workers backward on cost-of-living adjustments.